The present invention relates generally to optical recording/reproducing of information signals, and more particularly to an information signal recording medium having pits corresponding to information signals,-and recording apparatus for optically forming the pits thereon in accordance with the information signals and reproducing apparatus for optically reproducing the information signals therefrom.
Various types of optical recording/reproducing systems have been developed to optically record information signals by pits formed in concave or convex configuration on an information medium and to optically reproduce the information signals from the pits recorded thereon. One known reproducing system is a so-called LV system which illuminates an information signal recording medium with a light spot having a diameter greater in dimension than the width of the pits recorded thereon. Another known reproducing system is a so-called differential system which is arranged to obtain a reproduction signal by subtraction between the output signals of two divided photo deflectors receiving light reflected from an information signal recording medium due to application of a light spot whose diameter is smaller in dimension than the width of the pits. Both the systems respectively have advantages and disadvantages, and therefore, it would be advantageous to provide an optical recording/reproducing system having only the advantages of both the systems. However, difficulty is encountered to meet the requirement because there is a great difference between the characteristics of both the systems. Thus, a further improvement would be required from the viewpoint of meeting the requirements imposed in resolution of the disadvantages of the conventional information signal recording/reproducing systems.